Brake-valve device



May 25, 1926.

EXHAUST 585,819 T. B ARTY ET, AL

BRAKE VALVE DEVICE Filed August 2o, 1924 0D N INVENTORS THoMQr--D BAR-rv FRANK ABURRows ATTORN Patented May25, 1926.

f ori-ica THOMAS BARTY AND FRANK A. BURROWS, OF LONDON, ENGLAND, ASSIGNORS T0 THE WESVTINGHOUSE AIR BRAKE COMPANY, 0F WILMERDING, PENNSYLVANIA, A COR- PORATION 0F PENNSYLVANIA.

BRAKE-VALVE' DEVICE.

Application tiled-August 20, 1924-. Serial No. 733,085.

rThis invention relates to brake valves for luid pressure braking apparatus, and has for its object to provide an improved pedal operated brake valve device for controlling the fluid pressure brakes, particularly o a motor vehicle.

ln the accompanying drawing, the single figure is a sectional view of a brake valve device embodying our improvement.`

The improved brake' valve device may comprise a hollow body portion 1, having a horizontal lange2 at its upper end. |llhe lower end of the body portionis traversed by an axial passage 3, in which is located an inlet valve 4 of the poppet type adapted to cooperate with a valve seat formed at the upper endof an enlarged section of the axial passage 3.

'lhe inlet valve 4 is normally held in cngageinent with its valveseat by means of a coil spring 5, interposed between the lower. end of the valve and the upper end of an inlet nipple screw 6, which is threaded into the lower end 'of the enlarged section of the axial passage 3 v 'll`he upper end ot the body ortion 1 is closed by a cover .7 having a ange 8. A flexible diaphragm 9 isinter rosed between the flanges 2 and 8 and the anges are secured together by bolts 10.

rll`he cover 7 is provided with an` upwardly extending annular flange 11-whch serves as a guide for a piston 12 having a stem 13 extending downwa dly throu h the diaphragm 9'and secured thereto y a nut 111. The stem 13 of the piston 12 also extends upwardly in the formof a tubular element, the interior of which contains at its lower end an exhaust valve 15 of the poppet type. The exhaust valve 15 cooperates with a va ve seat formed in the piston stem and controls communication lbetween the vinterior of the tubular element and an axial passage \16 formed in the' lower valve stem and terminating in one or more apertures 17 opening into the interior ot the valve body, belowI the diaphragm 9.'

rlhe interior of the tubular element above the exhaust valve 15 is open tothe atmos- 'phere through orts 1S and vthe exhaust valve is provide with an upwardly extending stem 19, surrounded by a coll spring 20, tending to maintain the valve 15 seated.

`(not shown) The spring 2O is interposed between the valve 15 and the lower end of a screw plug 21, the stem 19 projecting through said plug.

The upper end of the exhaust valve 15 also loosely passes through an aperture in one endet a curved member 22, the opposite end of which is pivotally mounted on the cover plate 7a nthe pivot pin 23 of the member 22, one end of an operating pedal 24 is supported, said pedal being adapted to engage in its raised position with the underside ot the curved member 22 and thus raise the exhaust valve stem 19 by means of a. nut 25 applied to the upper end of the stem.

rlllie tubular element of piston 12 is surrounded loy a coil spring 26 interposed between the piston 12 and a flanged Vcollar 27, which loosely surrounds said tubular element and is arranged on the underside ofthe pedal 24:.

The interior of the valve body 1 below the diaphragm 9 communicates through a. pipe 28 with a brake chamber of the braking ap.

paratus, and the inlet nipple 6 is connected through pipe 29 with(9 a reservoir or other source of Huid under pressure.

lin operation, when the pedal 2e is in its normal or raised position in which it is maintained by a coil springSO, interposed between the pedal and the Hoor ot the vehicle, the pedal serves to maintain the member 22 in its upper position -in which it raises the exhaust valve 15, clear ot its seat against the action of its spring 20. As a result, the brake chamber or brake cylinder is vented to the atmosphere throu h pipe 28, the ports 17, axial passage 16 an the exhaust orts 18.

1n order to app y the brakes, the pedal 24 is depressed, thus permitting the member 22 to descend and the exhaust valve 15'to seat under the action of spring 20. The continued depression of pedal 24: then causes the under face of the dal to engage the collar 27 and thereby e ect the compression of spring 26. A s a result, the piston 12 moves downwardly until the lower extended end of the stem 13 engages the upper end of the inlet valve4 which-1s then moved from its seat against the action of spring 5.

Fluid lunder pressure is now admitted from the source of fluid under through pipe'29 to vthe chamber ow diaioa phragm 9 and is thence supplied throughv mitting the inlet valve 4 to seat and prevent the further supply of fluid to the brake chamber.

If a higher brake pressure is desired, the pedal 24 is further depressed, thus causing the inlet valve 4 to be again opened and then afterward closed, when the brake pressure-has been correspondingly increased.

In order to release the brake,1 the pedal 24 is released and allowed to return to its normal position, whereupon the member 22 will be operated to open the exhaust valve 15 and permit the release of fluidy from the brake chamber.

The action of the spring 20 can be adjusted by means of the plug 21 so that the pressure with which the valve 15 is held closed during an application of the brakes can be regulated, as desired.

In the event ofthe pressure in the brake chamber exceeding that for which lthe spring 20 may be adjusted, the exhaustv valve 15A will be opened and this will prevent an excessive brake pressure from being developed.

Having now described our invention, what we claim as new and desire to secure by Letters Patent, is i l. A brake valve device for controlling the admission of fluid under pressure to and its exhaust from a brake chamber and including an exhaust valve operated at apredetermined pressure in the brake chamber for releasing fluid from the brake chamber. 2. A brake valve device for controlling the admission of fluid under. pressure to and its exhaust from a brake chamber and in# cluding an exhaust valve subject to the op`l posing pressures of the brake chamber and a springand operated to 'vent fluid from the brake chamber in excess of the setting of the spring.

3. A brake valve device for controlling the. admission of fluid under pressure to and `its exhaust from a brake chamber and including an exhaust valve for controlling the exhaust of fluid from the brake chamber and subjectl to the opposing pressures' of the brake chamber and a spring whereby the Aits exhaust from a brake chamber and including a release valve, a spring tending to close said valve, a member operatively connected to said valve, aspring, and an operating lever actuated b said spring upon release of the lever by the operator for operating said member toopen said valve.

6. A brake valve'device for controlling the admission of fluid'under pressure to and its exhaust from a brake chamber and including an exhaust valve forreleasing Huid from the brake chamber in releasing the brakes and operated when the brakes are applied to vent fluid from the brake chamber upon a predetermined increase in pressure in the brake chamber.

7. A brake valve device comprising a casing, a flexible diaphragm in said casing, a fluid inlet valve controlled by said diaphragm, an exhaust valve, and a member movable with said diaphragm and containing the seat for said exhaust valve.

8. A brake valve device comprising a casing, a flexible diaphragm in said casing, a fluid inlet valve controlled by said diaphragm, an exhaust valve, a spring acting on said exhaust valve tending to seat same. and a member movable with said diaphragm and containing'the'seat for said exhaust valve.

9. A brake valve device comprising a casing. a flexible diaphragm in said casing, a spring -acting on said diaphragm, a fluid inlet valve controlled by said diaphragm, an operating lever acting-on said spring, an exhaust valve, a member associated with said diaphragm and having a seat for said exhaust valve, a spring tending to seat said exhaust valve, and an arm operated by said lever for opening said exhaust valve.

In testimony whereof we have hereunto set our hands.

THGMAS BARTY. FRANK A. BURROWS. 

